House of cards

How the wThe murderous gunshots of the Serbian activist, Gavrilo Princip, rang out on 28 June 1914. As the Habsburg heir Franz Ferdinand lay dead, the Austro-Hungarian Empire declared war on Serbia. As far as the Austrians were concerned, this was a matter simply for the politics of their corner of eastern Europe. They could not foresee that this initial event was to have a momentous impact on the rest of the world.
Russian trade interests
The Bosporus and Dardanelles trade routes, which linked the east with Europe, guaranteed that Russia would be locked into any territorial struggles of the Balkans, if they were to protect their own interests.
Bosnia, Herzegovina and Serbia were main players in this strategically important yet volatile region, and a precarious structure of alliances between rival empires held the area in check. Though Russia had played diplomatic games with Austria-Hungary regarding the treatment of the Balkans, they were set against each other when Austria-Hungary finally annexed Serbia in 1908.
The Austro-Hungarian declaration of war against Serbia following the shooting of Franz Ferdinand automatically drew Russia into the war through their Slavic alliance.
No going back
Germany then followed in support of Austria. What looked like another Balkan war was destined to break into a full world war before it had even started.
France supported their pact with Russia and in return was invaded by Germany.
As Germany wheeled through Belgium, they broke another treaty in which Britain had agreed to protect the neutrality of the Belgian state. Within a matter of weeks the snowball effect had drawn a large part of the world into conflict.
Germany primed for war
Before the Serbian uprising, Germany, like most of the other European nations, already held plans for attacking neighbours should the need arise. Germany was a relatively new empire, which had come about as a result of the alternate bullying and diplomacy of Bismarck, the prime minister of Prussia under Kaiser Wilhelm I.
German actions to expand territory and influence before the war had already heated up tensions with Britain and America, while France was also still smarting from a Prussian campaign that had lost them the region of Alsace-Lorraine in the 1870s.
With tensions running high on the home front, and a desire to expand the German Empire even further, Kaiser Wilhelm II encouraged plans for a war as the best way to solve his problems. The Schlieffen Plan, drawn up by the Army Chief of Staff, Alfred von Schlieffen, was a carefully measured sequence of events that was to be set in motion in the event of a European war. Counting on both Russia and France joining the action, the Schlieffen Plan banked on a slow Russian mobilisation that would allow for the capturing of France first.
On 3 August 1914, Germany declared war on France to back Austria-Hungary. By 23 August, German troops were streaming across Belgium and onto French soilorld collapsed into war